Locking device for straps



1965 JEAN-VICTOR CATTIN 3,209,423

LOCKING DEVICE FOR STRAPS Filed Jan. 21 1964 INYENTOR Jean-vlcror Catnn BY j KM ATTORNEYS United States Patent 1,0 4 Claims. (Cl. 24-181) The present invention relates to a locking device for straps, particularly for watch bracelets, collars, belts etc., in which in the closed condition of the strap one or several projections such as, for instance, pins or teeth on the side of the one strap end portion are engaged in one or more recesses such as, for instance, holes on the side of the other strap end portion and are secured in this engaged position by means of a slider.

In prior locking devices of the kind referred to, the projections are either directly fixed to the one strap end portion in the shape of pins or they are cut from this strap end portion in the form of ribs. In closed condition of the strap, the slider embraces both strap end portions. Therefore, there is not only an undesired thickening in reach of the locking device but also special provisions must be taken for providing the projections on the strap. An ordinary belt or a usual watch bracelet from leather or plastics can, therefore, not be equipped with such a locking device without that these special provisions are taken, such as fixing pins or cutting ribs on the strap.

The invention allows to remedy these inconveniences. The locking device according to the invention is characterised by a buckle member mounted on the one strap end portion and projectingfrom this portion, the said buckle member having one or several projections such as, for instance, teeth, pins or the like which in the closed condition of the strap are engaged in a hole or holes of the other strap end portion, the said slider, in closed condition of the strap, embracing only the said other strap end portion and the said buckle member.

Due to the invention the thickness is reduced in each of the locking devices compared with the prior means. Since the buckle member can be mounted on the one strap end portion in the same manner as a usual buckle, eg by forming a loop and by agglutinating or sewing together the extremities of the loop-halves, the locking device according to the invention can be used with any usual strap having a row of holes, without previously taking special provisions on the strap itself.

The accompanying drawing illustrates by way of example, one embodiment of the locking device according to the invention, provided on a strap in the shape of a belt or a watch bracelet made of leather or plastics.

FIG. 1 is a perspective representation of the two end portions of the strap, showing those surfaces of the end portions which, on the strap being in closed condition, are turned towards each other.

FIG. 2 is a top view of the strap end portions in closed condition of the strap.

FIG. 3 is a section along the line IIIIII of FIG. 2, on a larger scale than FIG. 2, and

FIG. 4 is a section along the line lV-lV of FIG. 2, on a larger scale than FIG. 2.

A flat metallic buckle member 2 having T-shape in plan View, is fixed to the strap end portion 1. The broader portion 3 of the buckle member 2 has a slot 4. The end portion 1 goes through the slot 4 and is bent back to form a loop 5. The extremities of the two loop-halves may be agglutinated, sewed together or interconnected in any other suitable way. In other words, the buckle member 2 is fixed to the end 1 in a manner used with known buckles without any special pre-treatment of the strap end ice portion. In another embodiment the buckle member 2 may be mounted on the end 1 -by means of pins as, 'for instance, used for mounting a watch bracelet to the horns of the watchcase. Projections in the shape of two teeth 7 are bent out of the narrower portion 6 of the T-shaped buckle member 2. The buckle member 2 may be produced in one piece in a single punching and bending operation. In certain cases, a single tooth 7 may be suflicient or one or several pins may be substituted for one or several teeth.

The other strap end portion 8 has 'a row of holes 9 as, for instance, usual in belts and watch bracelets. Adjacent holes 9 of this row have the same distance from each other as have the teeth 7 from each other. The cross section of the holes 9 corresponds to that of the teeth 7. A metallic slider 10 is shiftably mounted along the strap end portion 8 and embraces this portion only so far that a slot 12 remains open between the edges 11 of the slider in order to allow the teeth 7 entering completely into the holes 9 on the strap being in closed condition (FIG. 4). Between its guides 13 the slider 10 has an elevated middle portion 14 to provide between this middle portion and the end portion 8 of the strap a space for receiving the plate-shaped portion 6 of the buckle member 2.

For closing the strap by means of the locking device, at first the slider 10 is displaced along the strap end portion 8 until it arrives immediately at the right side (FIG. 1) of the hole 9 into which the tooth 7 remote from the portion 3 is to be inserted. Afterwards, the buckle member 2 is brought onto the strap end portion 8 and the teeth 7 are inserted into the two desired holes 9, whereupon the slider 10 is shifted onto the portion 6 of the buckle member 2 so that the locking device is now closed. For additionally securing the slider 10 in its locking position it may be suitable to slightly curve the portion 6, for instance, in longitudinal direction. Under certain circumstances, it may be desirable that only the teeth faces 15 turned towards each other bear against corresponding faces of the holes 9 (FIG. 3).

As may especially be seen from FIGS. 3 and 4, the slider 10, in locking position, only embraces the strap end portion 8 and the buckle member 2 projecting beyond the extremity of the portion 1, i.e., the slider 10 does not embrace the end portion 1. Therefore, the locked portion of the strap is thin compared with prior straps, especially if the portion 6 of the buckle member 2 is thinner than the strap itself. Moreover, as seen in FIGS. 2 and 3, the extremity 16 of the strap end portion 8 lies beneath the end portion 1, i.e., is hidden by the portion 1. The flat locking device has also no portions which might be caught on clothes or on any other object.

For opening the locking device the slider 10 is simply shifted in the other direction and the teeth 7 are lifted out of the holes 9.

I claim:

1. A locking device for straps having two ends to be joined, particularly watch bracelets, collars, belts and the like, comprising a substantially flat buckle member having means for securement to one strap end so as to project therefrom in the plane there-of, at least one projection protruding from the plane of a portion of said buckle member for engagement in a hole of the second strap end, a slider having channel-shaped guides at its sides for slideablyembracing only the edges of said second strap end, and a center portion between said guides raised to provide a space between said guides for slideably receiving said portion of said buckle member carrying said projection, whereby said slider, in the closed and locked condition of the strap, secures said projection engaged in said hole and surrounds only said second strap end and said portion of said buckle member.

2. A locking device as claimed in claim 1, wherein the said buckle member has a broad portion carrying said means for securement to one strap end and said portion carrying said projection is a narrow portion, said broad and narrow portions being disposed to form a T, whereby, in the closed and locked condition of the strap, said slider surrounds only said second strap end and said narrow portion of the buckle member.

3. A locking device as claimed in claim 1, wherein said channel-shaped guides on the slider comprise in turned side edges spaced apart to permit entry therebetween of said projection when it passes completely through a hole in the strap and the strap is in closed and locked condition.

4. A locking device as claimed in claim 2, wherein said narrow portion of the buckle member is slightly curved, whereby to increase the friction of locking engagement with said slider.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS Finland.

15 WILLIAM FELDMAN, Primary Examiner.

BOBBY R. GAY, Examiner. 

1. A LOCKING DEVICE FOR STRAPS HAVING TWO ENDS TO BE JOINED, PARTICULARLY WATCH BRACELETS, COLLARS, BELTS AND THE LIKE, COMPRISING A SUBSTANTIALLY FLAT BUCKLE MEMBER HAVING MEANS FOR SECUREMENT TO ONE STRAP END SO AS TO PROJECT THEREFROM IN THE PLANE THEREOF, AT LEAST ONE PROJECTION PROTRUDING FROM THE PLANE OF A PORTION OF SAID BUCKLE MEMBER FOR ENGAGEMENT IN A HOLE OF THE SECOND STRAP END, A SLIDER HAVING CHANNEL-SHAPED GUIDES AT ITS SIDES FOR SLIDEABLY EMBRACING ONLY THE EDGES OF SAID SECOND STRAP END, AND A CENTER PORTION BETWEEN SAID GUIDES RAISED TO PROVIDE A SPACE BETWEEN SAID GUIDES FOR 